Summary of work: The BLSA data set of 34 years of experience with the diagnostic tests for diabetes and with outcome variables (conversion to clinical diabetes, coronary heart disease incidence, mortality) is the most comprehensive experience in men and women across the adult age span. An analysis of these data were provided to the Expert Committee of the American Diabetes Association. These data were cited in the July 1997 publication of new criteria for the diagnosis of diabetes. These data were also provided to a WHO Committee which is expected to issue its report in the winter of 1997-98. The Diabetes Prevention Program is in the middle of its recruitment phase. Approximately 10% of the randomized participants are age 65 or over. Meetings have been held with recruitment consultants to devise strategies for an acceleration in the recruitment of older subjects. The ADA revision of diagnostic standards caught the DPP in mid-stream since a fraction of those already recruited (those with fasting glucose values of 126 to 139 mg/dl) converted to "instant diabetics" at entry. Nevertheless overall monthly recruitment goals are on target. Analysis of glycosylated hemoglobin and of microalbuminuria have been initiated. These tests are performed on all participants on each visit. Both of these substances undergo changes on frozen storage; techniques are being explored that will allow reliable retrospective analysis of the banked blood and urine samples. Comprehensive inventory of all banked samples was initiated. It is anticipated that it will be completed by December 1998.